Custom made dental abutments, such as crowns or bridges for mounting on an implant fastened in the jaw bone of a patient, are commonly manufactured based on a scanning. A scanning is performed of a scan body element or scanning abutment mounted on an implant analog in a mould of the patient's mouth, i.e. outside the patient's mouth. Alternatively, the scanning can be performed in the mouth of the patient with the scan body element mounted on an implant which has been implanted in the jaw bone of the patient, i.e. inter-orally. The scanning of a recognizable feature on a surface of the scan body element serves to provide a precise information of the position and orientation of the scan body element, and thereby also providing information of the position and orientation of the implant or implant analog, so as to enable manufacturing of a custom abutment that fits precisely onto the implant.
A known scan body element includes a threaded base part which is screwed onto the implant. Once the base part has been fastened to the implant analog, the dentist or surgeon manually positions and presses a polymeric cap onto an upper portion of the base part. The polymeric cap has features recognizable in a subsequent scanning. An example of such scan body element is shown in EP 2 130 514 A1.
However, it appears that this system provides a rather poor precision in the scanning result with respect to the orientation of the implant, as the scan element is mounted on a further part screwed into the implant, thus introducing a possible error in determination of tilt angle of the implant. Therefore, the resulting dental bridge or bar manufactured based on such scan may suffer from imprecise fitting onto the implant which may cause various health problems, e.g. infections and bone deterioration, thus providing additional costs and pain for the patient. In general, a very high precision is required, down to a tolerance less than e.g. 5-6 μm.
Furthermore, it can be a rather cumbersome process to fasten each part necessary to do the scan individually on the implant, especially when the scanning is performed inter-orally.